Electropneumatic paintball gun, method of making and operating, and retrofit kit assembly

ABSTRACT

An electro-pneumatically operated paint ball gun operates without the use of a mechanical sear, and includes a pneumatically operated hammer assembly effective to bump open a discharge valve and fire the gun. A programmable, microprocessor-based controller allows default values for time intervals of operation of the gun to be programmed, and also allows a user of the gun to access and change default values so that the operation of the gun can be modified to better meet the user&#39;s preferences. A cyclic rate of fire of as much as 30 paint ball shots per second or more is possible with a paint ball gun according to this invention. Further, a retrofit kit assembly provides for conversion of a conventional “autococker” type of paint ball gun into a gun embodying the present invention.

FIELD OF THE INVENTION

The invention relates to a pneumatic marker or paint ball gun, to amethod of making and operating such a paint ball gun, and to a retrofitkit for converting a conventional paintball gun to embody the improvedstructure and operation of this invention.

BACKGROUND OF THE INVENTION

Paint ball guns were originally developed for marking uses such asforestry and cattle ranching, in which frangible projectiles or paintballs were fired against trees to be harvested or cattle to be taken tomarket, for example. For this reason, the paint ball guns themselves arefrequently referred to as “markers.” But, more recently paint ball gunsare much more widely used in various recreational environments, such assimulated war games wherein it is the intent to shoot at an opposingplayer with the paint ball gun, thus marking this opposing player with aparticular color of paint from a frangible paint ball.

Paint ball guns using compressed air or gas for power are well known.Until recently, most paint ball guns were pneumatically powered,mechanically operated guns. The entry of electro-pneumatically operatedpaint ball guns provided more consistent and better performing guns forthe recreational market. An electro-pneumatic paint ball gun providesimproved performance with fewer component malfunctions than the earliermechanical-pneumatic paint ball guns. However, a common problem with theconventional electro-pneumatic paint ball guns is that they use amechanical sear device to release a hammer. The hammer is spring loadedto a position at which it impacts a valve stem, opening a flow path forhigh pressure gas to communicate to a paint ball, propelling the paintball through and from a barrel of the gun. The adjustment of theengagement and release of the mechanical hammer and sear remains anuncertain element of conventional paint ball gun operation, requiringfrequent adjustments in order to operate at high cyclic rates.

A more recent paint ball gun is shown in U.S. Pat. No. 6,532,949(hereinafter, the “949” patent). In the '949 patent, a hammer of a paintball gun is moved in each of two opposite directions by respective endsof a rod member, to which respective pneumatic pressures are appliedsequentially by a solenoid valve. In this 949 patent, the hammer must bemoved in each direction of its stroke by a respective pneumaticpressure, and these respective pneumatic pressures must be sequentiallycontrolled by a solenoid valve.

SUMMARY OF THE INVENTION

In view of the deficiencies of the related art, it is an object for thisinvention to mitigate or eliminate at least one of these deficiencies.

Specifically, it is an object for this invention to provide a paint ballgun having no mechanical sear for releasing a hammer to discharge thepaint gun.

Another object for this invention is to provide such a paint ball gun inwhich a hammer is pneumatically driven in one direction only todischarge the paint ball gun, and is driven in the opposite direction bya biasing spring in order to prepare the paint ball gun for its nextdischarge.

Still another object for this invention is to provide such a paint ballgun in which a microprocessor controller may be accessed by the user ofthe paint ball gun in order to fine tune the time sequence of events inthe operation of the paint gull.

The present invention addresses the deficiencies of the conventionaltechnology by providing an electro-pneumatically operated paint ball gunhaving a main body defining a first bore for receiving a paint ball. Thefirst bore also receives a reciprocable bolt assembly which inrespective first and second positions relative to the main body closesand opens a breech of the gun. A feed inlet opening to the first bore isprovided for providing a supply of paint balls to the breech, and themain body further defines a second bore spaced below and substantiallyparallel with the first bore. A passage communicates from the secondbore to the breech. A pneumatic discharge valve is disposed in thesecond bore, the pneumatic discharge valve including a seat member, anda poppet valve member sealingly engaging in a first position upon theseat member to close communication of pressurized gas from a sourcethereof to the breech via the passage. This poppet valve member includesa poppet valve stem extending through the seat member rearwardly of thegun. A pneumatic hammer assembly also is disposed in the second bore aftof the discharge valve, the pneumatic hammer assembly including a sleevemember defining a bore, a hammer member reciprocally and sealinglymovable in the sleeve member bore and cooperating therewith to define avariable-volume chamber having a minimum volume with the hammer memberin a first position. A spring is disposed in the second bore between thepneumatic hammer assembly and the pneumatic discharge valve and biasesthe hammer member to the first position. The hammer member in responseto receipt of pressurized gas in the sleeve bore moves axially forwardlyof the gun to a second position to abut the poppet valve stem, thusunseating the poppet valve member to a second position and opening thedischarge valve to communicate pressurized gas to the breech via thepassage.

Additional objects and advantages of the present invention will becomeapparent to those ordinarily skilled in the pertinent arts upon readingthe following detailed description of a particularly preferredembodiment of the invention, which illustrates the best modecontemplated for practicing the invention, taken in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevation view, partially in cross section, of a paintball gun embodying the present invention, and shows the paint ball gunin the condition it has immediately preparatory to filing a paint ball;

FIG. 2 is a side elevation view similar to FIG. 1, and also partially incross section, and shows the paint ball gun in the condition it hasimmediately after the moment the trigger is pulled in order to fire apaint ball;

FIG. 3 is a side elevation view similar to FIGS. 1 and 2, also partiallyin cross section, and shows the paint ball gun in the condition it hasat the moment pressurized gas is communicated to a paint ball within thebarrel of the gun, thus to fire this paint ball from the barrel;

FIG. 3A is an enlarged fragmentary view of a portion of FIG. 3;

FIG. 4 is another side elevation view similar to FIGS. 1-3, and is alsopartially in cross section, and shows the paint ball gun in thecondition it has next in sequence after the condition of FIG. 3;

FIG. 5 is a side elevation view similar to FIGS. 1-4, also partially incross section, and shows the paint ball gun in the condition it has nextin sequence after that of FIG. 4, and during which a new paint ball isloaded into the breech of the gun;

FIG. 6 is yet another side elevation view similar to FIGS. 1-5, and isalso partially in cross section, and shows the paint ball gun in thecondition it has next in sequence after the condition of FIG. 5, whichwill complete a cycle of operation, bringing the paint ball gun to thecondition seen in FIG. 1;

FIG. 7 is a timing diagram of the operation of the paint ball gun seenin FIGS. 1-6; and

FIG. 8 is a diagrammatic representation of a microprocessor controlsystem of the present inventive paint ball gun, which controls itsoperation and which also allows for fine tuning of timing of events inthe sequence of operation of the gun in order to maximize the operationcharacteristics of particular guns and best suit the wishes ofparticular shooters.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to the drawing Figures in conjunction with one another, andfirst considering especially FIG. 1, a paint ball gun 10 includes a mainbody 12, with a grip frame 14 pivotally carrying a trigger 16 anddefining a trigger guard 18. A barrel 20 is attached to the main body12, and defines a breech opening 22 a by which a paint ball is received,and muzzle opening 22 b by which a paint ball is discharged. A gas inletregulator body 24 is also attached to the main body 12, and providescommunication via an inlet 24 a (arrowed on FIG. 1) with a source ofhigh pressure gas (not shown in the drawing Figures) for powering thepaint ball gun 10.

A paint ball hopper and feeding device (also not seen in the drawingFigures) can be mounted on the top of the main body 12, feedingpaintballs 26 into the gun 10 via an upper feed tube 28 defining a feedport 30. The feed port 30 opens into a top one 32 of two substantiallyparallel and vertically spaced bores (i.e., bores 32 and 34) defined bythe main body 12. The barrel 20 is received at a rear portion thereofinto the front of bore 32, and is able to receive and discharge thepaint balls 26. A bolt assembly 36 is reciprocally and sealinglyreceived into the rear portion of bore 32, and cooperates with the feedport 30 and with the barrel 20 at breech opening 22 a to define a breechchamber 38 in which a paint ball is sealingly received and is held untilit is forcefully discharged from the gun 10, viewing FIG. 1.

The gas inlet regulator 24 provides pressurized gas (i.e., compressedair, nitrogen, or carbon dioxide, for example) into a bore portion 34 a.A front part of the bore portion 34 a communicates via a manifold piece40 (which sealingly closes this bore at the front of the gun 10) with apair of low-pressure pressure regulators 42 and 44. Also mounted to themanifold piece 40 is a 4-way solenoid valve assembly 46, and adual-acting pneumatic cylinder or ram 48. The ram 48 has an internalpiston (not shown in the drawing Figures) connecting operably to areciprocable link rod 50. The link rod 50 extends rearwardly of the gun10 (i.e., leftwardly viewing the drawing FIGS. 1-6) to connect operablyto a back block part 36 a of bolt assembly 36. Thus, a portion of thebolt assembly 36 is reciprocable selectively in bore 32 under control ofthe ram 48 and 4-way solenoid valve 46 to move the bolt assembly betweenthe closed position seen in FIG. 1 and the opened position seen in FIG.5. As is seen in FIG. 5, a paint ball 26 is received via the feed port30 into the breech chamber 38 when the bolt assembly 36 is fully opened.

Returning to a consideration of FIG. 1, it is seen that the bore portion34 a also communicates rearwardly to a larger diameter bore portion 34b, which serves to define a volume accumulator or chamber 34 c, storinga quantity of pressurized gas in preparation for firing of the gun 10. Adischarge valve assembly 52 is sealingly received in the bore 34 aft ofthe bore portion 34 b, and includes a seat member 54 movably receiving apoppet valve member 56. The poppet valve member 56 includes an elongatestem portion 58 extending rearwardly through the seat member 54. Theseat member 54 also defines a flow passage 60 communicating via apassage 62 defined by the housing 12 between the bores 32 and 34, tocommunicate pressurized gas from chamber 34 c via a passage 36 b of thebolt assembly 36 and to the breech chamber 38 when the poppet valvemember 56 is unseated, as will be further explained below. A coil spring64 yieldably urges the poppet valve member 56 into sealing engagementwith the seat member 54.

Also received into the bore 34 at an aft portion 34 d thereof is apneumatic hammer assembly 66. The details of this pneumatic hammerassembly are best viewed in FIGS. 1 and 3, and especially in FIG. 3 a.This pneumatic hammer assembly 66 includes a sleeve member 68 sealinglyreceived into the bore portion 34 d, and which is there retained in thisaft bore portion 34 d by a radially extending screw 70 (not seen in thedrawing Figures, but indicated by an arrowed reference number) extendingthrough an aligning hole in the housing 12 and threadably engaging intothe sleeve member 68. This sleeve member includes a pair of spaced apartseal members 72 and 74, which cooperatively bound an annular chamber 76therebetween. Within the sleeve member 68 is defined a blind bore 78opening forwardly on the sleeve member within bore portion 34 d. Amultitude of ports 80 open from the annular chamber 76 into the bore 78adjacent the aft end (i.e., the blind end) thereof.

Reciprocally received into the bore 78 is the aft end portion 82 a of ahammer member 82. The aft end portion 82 a defines a seal groove 82 b,and carries a seal member 82 c which is sealingly movable within thesleeve member 68. The aft end portion 82 a cooperates with the sleevemember 68 to define an expansible chamber 82 d. The ports 80 communicatewith chamber 82 d. This hammer member 82 also includes an enlargedhammer head portion 82 e disposed outwardly (i.e., forwardly) of thesleeve member 68 and within bore portion 34 d. At the forward end ofthis hammer member 82, the hammer head portion 82 b defines an abutmentsurface 82 f. In the first position of the hammer member 82 seen in FIG.1, the abutment surface is spaced from valve stem 58. However, as isseen in FIG. 3, the hammer member 82 is movable to a second position(FIGS. 3 and 3 a) to abut on stem 58 at abutment surface 82 f, thusunseating the poppet valve member 56 and opening the discharge valve 52.A coil spring 84 is received into bore portion 34 d between the seatmember 52 and the head 82 e of hammer member 82 in order to yieldablyurge or bias the hammer member 82 to its first position, as is seen inFIGS. 1, 2, and 4-6.

Further considering the drawing Figures, it is seen that the grip frame14 houses an electronic and valving assembly 86. This assembly 86includes a 3-way, normally closed solenoid valve, indicated with thenumeral 88. The solenoid valve 88 has an inlet port 88 a, an outlet port88 b communicating to port 88 a when the valve is energized, and anoutlet port 88 c to ambient (indicated by the arrowed numeral on thedrawing Figures), communicating with port 88 b when the valve 88 isde-energized. Assembly 86 also includes a circuit board 90 including amicroprocessor based control system, indicated with arrowed numeral 92,and more particularly disclosed in FIG. 8. A switching device 94 isarranged to be activated by rearward movement of the trigger 16 (i.e.,by means of an interposed push rod 94 a) so as to discharge the gun 10,as is further explained below. It is to be noted that while theswitching device 94 is depicted in the present embodiment as includingor being a micro-switch, the invention is not so limited. For example,an electro-optical switching device may be alternatively employed.

Further considering the drawing Figures, it is seen that the regulator42 provides pressurized gas to a conduit or line 96 which extends to anormally open common port 46 a of the 4-way solenoid valve 46. Fromregulator 44 a line 100 extends to the normally closed port 88 a of the3-way solenoid valve 88. A line 104 extends from a normally open port 46b of the solenoid valve 46 to the rear connection of ram 48, thusnormally urging the ram, link rod, and bolt assembly 36 forwardly. Froma normally closed port 46 c of the solenoid valve 46 a line 106 extendsto a front connection at the ram 48. The solenoid valve 46 includes avent port 46 d to ambient (indicated by the arrowed numeral on thedrawing Figures), and to which the port 46 c communicates when thesolenoid 46 is de-energized, while the port 46 b communicates to ventport 46 d when the solenoid is energized.

Turning now to FIG. 8, details of the microprocessor control system 92included in the assembly 86 is presented with more particularity. Thissystem 92 includes a microprocessor 108, with associated memory 110, andan input facility or interface 112. The processor 108 also includes anoutput facility or interface 114. The input facility 112 receives aninput from the switch 94, responsive to rearward movement of the trigger16. This input facility can also receive an input (indicated witharrowed numeral 116) from an electric “eye” (i.e., from a light emittingdiode and photodiode or phototransistor combination) installed at thebreech chamber 38 and responsive to the presence of a paint ball) sothat the bolt assembly 36 is not closed on a paint ball that is in thefeed port 30, but which is not yet completely received into the chamber38. Such an electric eye is conventional, and is not illustrated in thedrawing Figures. However, it is to be understood that the use of such aneye prevents the bolt assembly 36 closing too early and cutting orfracturing a paint ball that is only partially fed into the gun 10.Those ordinarily skilled in the pertinent arts will know that the rateof feeding of individual paint balls via port 30 will depend in partupon whether the operator of the gun 10 is utilizing a simple gravityfeed paint ball hopper, or perhaps is using an electric feed paint ballhopper which provides a feeding assistance to the paint balls enteringport 30. Thus, the feed rate of paint balls via port 30 is a variable,to which the gun 10 is responsive, as will be further explained.

Further considering FIG. 8, it is seen that the input facility 112 alsoincludes a port 118 by which a user of the gun 10 may access the timingfunctions of the control system 92, so as to fine tune those timingfunctions to the user's preferences. As FIG. 8 illustrates, thecontroller 92 has output connections via the output facility 114 to eachof the solenoid valves 46 and 88 so as to control the operations andtiming of these solenoid valves, thus to control operation of the gun10. As those ordinarily skilled in the pertinent arts will understand,the output facility may provide output interface connections with otherfunctions of the gun 10, such as control of a stirring function of apaint ball hopper feeding paint balls to the gun 10.

Finally, considering FIG. 7, and referring also to FIGS. 1-6, it will beseen that the operation of the gun 10 is as follows: With a source ofhigh pressure gas connected to the inlet 24 a of the gas inlet regulator24, with a supply of paint balls 26 provided to the feed tube 28, andwith the controller 92 energized (i.e., by an on-board battery, forexample) the gun 10 is ready for shooting. In preparation for suchshooting, the operator can place a first paint ball 26 into the breechchamber 38 by manually grasping the knurled portion of the back blockpart 36 a and cycling the bolt assembly 36 rearwardly and then backforward to place a paint ball from feed port 30 into chamber 38,preparing the gun 10 for the condition of FIG. 1. In this condition ofFIG. 1, both solenoid valves 46 and 88 are de-energized, and the boltassembly is urged forward by pressurized gas communicating to line 104and to the rear connection of the ram 48. The hammer member 83 is alsoin its first position of FIG. 1. This is the “ready” condition seen atthe margins of FIG. 8.

Considering FIG. 2, and further considering the timing diagram of FIG.8, when the trigger 16 is pulled by the operator (indicated as event No.1 on FIG. 8), the control system 92 energizes solenoid valve 88, withthis valve requiring a time interval (indicated as V1, or variable 1, onFIG. 8) to switch pressurized gas from port 88 a to port 88 b. Thevariable V1 is expected to be from about 1 millisecond to about 5millisecond, and is substantially repeatable for a particular gunbecause it represents the response time of valve 88. The pressurized gascommunicated to port 88 b is communicated via a line 118 from port 88 b(indicated by the arrows on FIG. 2) to chamber 76, through the ports 80,and into chamber 82 d.

Thus, this pressurized fluid acting on the pneumatic hammer assembly 66moves the hammer member 82 to its second position, and “bumps” open thepoppet valve member 56 of discharge valve 52, communicating pressurizedgas from chamber 34 c to the breech chamber 38 via the seat member 54,passage 60 and passage 62.

Pressurized gas communicating to the breech chamber 38 discharges thepaint ball 26 from the gun 10 along barrel 20 (viewing particularly FIG.3). But, viewing FIG. 8 once again, it is seen that the time interval V2during which the solenoid valve 88 is energized is variable also. Thetime interval V2 may be programmed into the processor system 92 with adefault value providing positive operation of the firing action of thegun 10. However, the time interval V2 may also be accessed by a user ofthe gun 10 (i.e., via interface 118) in order to vary this time intervalas the user wishes in order to maximize performance of the particulargun 10.

Next, viewing FIG. 8, it is seen at event No. 2, the solenoid 88 isde-energized, which closes communication of pressurized gas to port 88b, and communicates pressurized gas from chamber 82 d to ambient via thevent port 88 c. This allows the spring 84 to move hammer member 82toward its first position, and allows discharge valve 52 to close, sothat residual pressure within the breech chamber 38 and barrel 20 beginsto decay as pressurized fluid flows from the muzzle of the gun 20following discharge of the paint ball 26. This is the condition of thegun 10 depicted particularly by FIG. 4.

While this pressure decay in the breech chamber 38 and barrel 20 istaking place, a time interval V3 is counting down. Time interval V3 willbe programmed to a default value, expected to be from about 0 (zero)millisecond to about 5 millisecond. But, time interval V3 may also beaccessed by a user of the gun 10 so that the operation of a particulargun 10 can be adjusted to the user's preferences.

At the end of time interval V3, event No. 3 (FIG. 8) is initiated by thecontroller 92. At the moment indicated at event No. 3 on the diagram ofFIG. 8, the solenoid valve 46 is energized, switching pressurized gasfrom the rear of ram 48 to the front of ram 48. Thus, the link rod 50 isforced rearwardly, and the bolt assembly 36 is moved rearwardly, viewingFIG. 5. At the full rearward position of the bolt assembly 36, a paintball 26 may enter via feed port 30 and be received into breech chamber38. The time interval required for the bolt assembly to move from itsclosed position of FIGS. 1-4, to its fully opened position of FIG. 5,and for a paint ball 26 to be received into breech chamber 38 via feedport 30 will vary dependent on a multitude of factors, as was mentionedearlier. For example, a gravity feed of paint balls will likely be muchslower than a power feed.

Also, in this respect it is important to note that immediately after ashot, the residual pressure in the breech chamber 38 is positive (i.e.,well above ambient), but this pressure decays rapidly as pressurized gasflows from the muzzle. If the bolt 36 is opened too early while thepositive pressure is still present, this positive pressure can resistthe entry of the next paint ball 26 into the breech chamber 38. However,after the positive pressure wave flows from the muzzle of the gun 10,this positive pressure is followed by a rarefaction wave (i.e., negativepressure wave) that moves along the barrel 20 from the muzzle toward thebreech chamber 38. If the bolt 36 is opened in synchronization with thearrival of this negative pressure wave at the breech chamber 38, thenthe next paint ball 26 can be assisted into the breech chamber by thenegative pressure wave. One factor that will influence the time ofarrival of the negative pressure wave at the breech chamber 38 is thelength of the barrel 20.

Subsequently, the time interval V4 counts down, viewing FIG. 8. Thevalue of time interval V4 is programmed to a default value, but if thegun 10 is operating with an input 116 to controller 92 (i.e., from anelectric eye sensing the presence of a paint ball in breech chamber 38)then the time interval V4 ends when this input 116 is provided. Again,the default value of time interval V4 may be accessed and changedaccording to the preferences of a particular user of the gun 10.

At the completion of time interval V4, at event No. 4, the solenoidvalve 46 is de-energized, and switches pressurized gas from the front ofram 48 to the rear of this ram, beginning the closing motion of boltassembly 36. As is seen in FIG. 6, once the bolt assembly 38 is fullyclosed with a new paint ball 26 in the breech chamber 38, the gun 10will have returned to its “ready” condition, prepared to fire yetanother paint ball shot. However, as FIG. 8 illustrates, the timeinterval V5 required for the full closing of the bolt assembly 38 maytake from about 5 millisecond to about 30 millisecond. Thus, the timeinterval V5 is also programmed to a default value insuring reliableoperation of the gun 10, but may also be accessed and adjusted by a userof the gun 10 in order to tune the gun to the user's preferences.

Further to the above, and with consideration of the timing diagram ofFIG. 8, it is important to understand that a paint ball gun according tothis invention may achieve a cyclic rate of as much as 30 firingoperations or more per second. Thus, dependent upon the type of paintball feed being employed, the skill of the operator in dithering thetrigger 16, and the timing factor “tuning” of a particular paint ballgun, the gun 10 may fire paint ball shots essentially like a fullyautomatic gun, at a cyclic rate of as much as 30 shot a second or more.

That is, as described, the gun is set up for semi-automatic operationbut it can readily be converted to select fire or fully automaticoperation in which the electronic control circuit 92 continuouslyrepeats the firing cycle whilst the trigger 16 is actuated. In this casethe rate of fire will depend solely on the length of the firing cycle.

Still further with consideration of FIG. 8, it is to be noted that byaccessing and adjusting the values (i.e., time intervals) of the timeperiods indicated as V1, V2, and V3, an operator of the gun 10 may timethe gun so that the rarefaction wave arrives at the breach of the gun atthe optimum time to ingest the new paint ball 26. That is, the new paintball can be literally sucked into the breach of the gun 10 (inassistance to gravity or such other feeding force as may be provided byan auto-feed device, for example). It is to be remembered that theopening movement of the bolt assembly 38 takes some short period of timeafter event No. 3, but this time period is repeatable. Thus, the timeperiod from the trigger pull (event No. 1) until the bolt 38 reaches itsfull open position is repeatable, and the relative timing of the openingof discharge valve 52 (i.e., the event that really starts the positivepressure wave in the gun 10, resulting in an inverting reflection at themuzzle, and the rarefaction wave then moving to the breach) until thebolt assembly 38 is open and receives the next paint ball 26, can beprecisely tuned using the present invention. Thus, this inventionprovides the possibility of precisely opening the bolt assembly 38 insynchronization with the arrival at the breach of a rarefaction waveingesting the next paintball, which could not heretofore be achieved.

Further, this invention provides a retrofit kit assembly (or kit ofparts) for converting a conventional paint ball gun of the “over andunder” bore design having a mechanical sear, and being commonly referredto as an “autococker” into a gun embodying the present invention. Thisretrofit kit of parts includes a new grip frame 14 with trigger 16 andtrigger guard 18, and having the internal electronics and valvingassembly 86 installed. As was disclosed above, the electronics andvalving assembly 86 includes circuit board 90. This circuit board 90carries microprocessor-based control system 92, as well as the triggerswitch 94. Also included in the retrofit kit of parts is the 4-waysolenoid valve 46, and a sufficient length of the conduit material forthe various interconnecting pneumatic lines as depicted and disclosedabove. Also, this retrofit kit of parts includes the pneumatic hammerassembly 66, with sleeve member 68 and hammer member 82. One or both ofthe regulators 44 and 46 may be included in the retrofit kit, dependingon the preferences of the user and the cyclic rate of fire that isdesired from the converted gun.

Thus, the present invention provides for a retrofit kit assembly thatcan be easily connected to a conventional “autococker” type of paintball gun body. The autococker type of paint ball gun bodies have the“over and under” bore design as depicted and described above. Thisretrofit kit of parts may be utilized along with the conventional partsof such an autococker paint ball gun in order to change a conventionalgun (which conventionally is of mechanical-pneumatic operation) into thebetter performing, electro-pneumatic and sear-less operation of thepresent invention.

While the invention has been described in connection with what ispresently considered to be the most practical and preferred embodiment,it is to be understood that the invention is not to be limited to thedisclosed embodiments but is intended to be limited only by the spiritand scope of the appended claims, giving full cognizance to equivalents,and to cover various modifications and equivalent arrangements as ispermitted under the law.

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 14. A method of operating apaintball gun having a high cyclic rate of fire, said paintball gunincluding a barrel member for discharge of said paintball and having adetermined length providing said barrel member with a characteristicfrequency of oscillation of air pressure waves between a breach openingand a muzzle opening of said barrel member, said gun further including abolt assembly controllably reciprocating between a closed first positionclosing said breach opening and an opened second position allowing a newpaint ball to enter said breach opening via a feed opening, and adischarge valve selectively providing pressurized gas to said barrel atsaid breach to discharge a paintball from said barrel, said methodincluding steps of: providing a pneumatic hammer assembly cooperablewith said discharge valve to controllably effect opening of thedischarge valve, providing said pneumatic hammer with a sleeve memberdefining a bore, a hammer member reciprocally and sealingly movable insaid sleeve member bore and cooperating therewith to define avariable-volume chamber having a minimum volume with said hammer memberin a first position, utilizing a spring to bias said hammer member tosaid first position, and synchronizing opening of said bolt assemblywith the arrival at said breach opening of a rarefaction air pressurewave, and utilizing this rarefaction air pressure wave to assist a newpaint ball into said breach opening.
 15. A retrofit kit assembly for usein converting a conventional “autococker” type of paintball gun having amain gun body into an electro-pneumatically operated paintball gunproviding an extraordinarily high cyclic rate of fire of paintballs fromsaid gun, said retrofit kit of parts including: a grip frame forattachment to said main gun body, said grip frame carrying a trigger andincluding a trigger guard, said grip frame also having an internalelectronics and valving assembly; said electronics and valving assemblyincluding a circuit board carrying a microprocessor-based control systemand a trigger switch cooperable with said trigger to provide an input tosaid control system in response to a trigger pull movement of saidtrigger; said electronics and valving assembly also including a 3-waysolenoid valve; a pneumatic hammer assembly receiving a pneumatic signalfrom said 3-way valve, said pneumatic hammer assembly including a sleevemember defining a bore, a hammer member reciprocally and sealinglymovable in said sleeve member bore and cooperating therewith to define avariable-volume chamber having a minimum volume with said hammer memberin a first position, said hammer member being movable in response toreceipt of said pneumatic signal from said 3-way valve to extendoutwardly of said sleeve member to a second position in which saidhammer member is cooperable with a discharge valve of said gun to opensaid discharge valve, and a spring for biasing said hammer member tosaid first position; a ram operably coupled with a bolt assembly of saidgun; and a 4-way solenoid valve providing opposite pneumatic signals tosaid ram for reciprocating said bolt assembly between closed and openedpositions; a regulator for providing pressurized air to said 3-waysolenoid valve; and a regulator for providing pressurized gas to said4-way solenoid valve.
 16. The retrofit kit assembly of claim 15 furtherincluding said electronics and valving assembly including a programmablecontroller selectively controlling said 3-way and said 4-way solenoidvalves.
 17. The retrofit kit assembly of claim 16 wherein saidprogrammable controller includes a microprocessor, and saidmicroprocessor is utilized to effect a first programmable time intervalbetween an event starting movement of said hammer member from its firstposition toward its second position, and a next subsequent eventstarting movement of said hammer member from its second position backtoward its first position.
 18. The retrofit kit assembly of claim 17wherein said programmable controller is utilized to effect a controlledvariable time interval between said first event and said second event.19. The retrofit kit assembly of claim 17 wherein said programmablecontroller is utilized to effect a controlled variable time intervalbetween said second event and a third event which starts movement ofsaid bolt assembly from said closed position toward said openedposition.
 20. The retrofit kit assembly of claim 19 wherein saidprogrammable controller is utilized to synchronizing opening of saidbolt assembly with the arrival at a breach opening of said gun of ararefaction air pressure wave, such that said rarefaction air pressurewave is effective to suck a new paint ball into said gun.
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